Accuracy of VirtualTouch Acoustic Radiation Force Impulse (ARFI) Imaging for the Diagnosis of Cirrhosis during Liver Ultrasonography

PURPOSE: VirtualTouch is a new technique recently proposed to evaluate liver stiffness during B-mode ultrasonography. The goal of the present study was to analyze the diagnostic accuracy of VirtualTouch in the diagnosis of cirrhosis and its correlation with transient elastography (Fibroscan). MATERIALS AND METHODS: A total of 133 patients with chronic liver disease were enrolled. 90 of 133 underwent VirtualTouch and transient elastography and 70 patients assessed with VirtualTouch were submitted to liver biopsy. Stiffness was assessed by both techniques in the right liver lobe. The diagnostic accuracy for cirrhosis was first assessed in the 90 patients submitted to transient elastography with > 13 kPa (47 % of patients) as diagnostic for cirrhosis values. The best cut-off for cirrhosis with VirtualTouch was then tested in the 70 patients with biopsy (cirrhosis in 38 % of patients). 41 patients were assessed by VirtualTouch by two different operators. RESULTS: The VirtualTouch values in controls, chronic hepatitis and cirrhosis were respectively 113, 147 and 255 cm/sec. The AUROC of liver VirtualTouch for the diagnosis of cirrhosis (reference Fibroscan) was 0.941 with 175 cm/sec as the best cut-off (sensitivity 93.0 %; specificity 85.1 %). VirtualTouch confirmed good performance also in patients with bioptic diagnosis of cirrhosis (AUROC 0.908, sensitivity 81.5 %, specificity 88.4 %,). The correlation of VirtualTouch with transient elastography was strict (r = 0.891) and the correlation in VirtualTouch measurements between two operators was also good (r = 0.874). CONCLUSION: VirtualTouch is able to identify the presence of cirrhosis with good accuracy, shows good interobserver reproducibility and the correlation of its values with those obtained by transient elastography with Fibroscan is good.